Swiss patent application CH 00834/89-7 discloses bale opening apparatus which includes an opening roller having its axis extending lengthwise with respect to a row of bales to be opened and being inclined downwardly toward an end of the row. In the bale opening machine proposed in this Swiss patent application the bales are pushed forward step-by-step to be cut away by the opening roller, and the opening roller is moved transversely with regard to the direction of movement of the bales to traverse across the widths of the bales. Several arrangements are possible. For example, several rows of bales may be disposed side-by-side or one above the other, and several inclined opening rollers may be used to open the bales in such rows.
The inclined opening of fiber bales has the specific advantage that the material is simultaneously opened from all areas of the bales so that a more or less constant amount is opened per time unit. The amount is, to a large extent, independent of the respective distribution of densities within the fiber bales. Therefore, the depth of the opening action to be accomplished during a pass of the opening roller transversely across the row of bales may be set on the basis of the amount of flocks to be cut away per time unit and may be kept constant from pass to pass of the roller. According to this proposal, the depth to be opened is establishing by the distance the row of bales is pushed forward toward the inclined opening roller in predetermined steps.
The conveying apparatus which performs the stepwise displacement of the fiber bales according to this former proposal is in the form of a revolving conveyor belt. Although such an arrangement is possible, it leads to relatively high costs, as the fiber bales to be displaced are relatively heavy and movement of the row of bales against the direction of intended displacement must be prevented because of the forces exerted by the opening roller on the front bales during the process of opening.
Such equipment can be constructed so that the apparatus is stable despite relatively low production costs and is reliable in day-to-day operation. The step length of the stepwise displacement may be set to a fixed value or adjusted variably without making the system excessively expensive, and the danger of the bale being pushed back during the opening process due to the forces prevailing during such process is effectively minimized.
Moreover, multiple units of such a conveying apparatus may be used in arrangement of modular design. The modules may be placed in several rows and various lengths side-by-side or behind each other depending on the size and the design of the bale opening machine.